In military and police firearms applications almost all of the ammunition consumed is used for training. For some training purposes, however, normal ammunition is not adequate. An alternative type of known training ammunition, represented by U.S. Pat. No. 5,359,937 (adopted herein by reference), fires a low-mass projectile relying on a special, low-energy cartridge designed to provide cycling of suitably-modified, recoil-operated automatic weapons.
An advantage of the low-energy training ammunition is that it has a shorter range and lower penetration capacity than standard ammunition. This permits use of smaller, less secure firing ranges as training facilities. If standard ammunition were accidentally employed in these facilities, unexpected dangers would arise from the increased striking power and range of such standard ammunition.
The weapon modifications required to permit cycling while firing low-energy training ammunition generally include replacing or modifying the barrel, and sometimes replacing or adding certain other components, depending on the weapon involved. These modifications also take safety into consideration. For example, in 9 mm automatic firearms, the caliber of the substitute barrel may be smaller than the diameter of the projectiles in standard 9 mm ammunition. If an attempt is made to chamber a standard round in such a training-adapted firearm, the design of the chamber and barrel will not normally permit entry of the standard projectile. This ensures that such modified weapons cannot fire standard, live ammunition.
The low-energy cartridge represented by U.S. Pat. No. 5,359,937, in combination with a substitute training barrel, allows normal recoil and cartridge case ejection through a blow-back action. Such a system, when firing appropriate marking cartridges, makes up an effective close-range, force-on-force training system. Hits, which are non-lethal, are denoted by red, blue or other coloured marks. This system enhances the realism and training value of interactive scenario tactical training because it allows trainees to use their service weapons in a representative manner in exercises simulating, for example, counter-terrorism, close quarters combat, urban fighting, protection of dignitaries, trench clearing, and fighting in wooded areas.
When firing standard ammunition, with its abundant associated energy, it is necessary in many weapons, particularly handguns, to lock the barrel to the slide during the beginning of their rearward motion for a period long enough for the projectile to exit the barrel muzzle while the breech is still closed. This allows the chamber pressure to drop before the breech opens to eject the spent cartridge case. A locking mechanism couples the slide and barrel together for the first portion of the recoil, and then releases the slide. Upon unlocking, the slide continues its rearward travel while the barrel stops in the proper position to receive the next round from the magazine to be chambered.
Associated with the barrel locking and unlocking with the slide in a standard weapon, there may also be an up-and-down vertical movement of the chamber end of the barrel. This pivoting motion may be caused by a cam located under the barrel. When in battery, the barrel is in its most upward position such that the center of the primer of the chambered round is aligned with the firing pin. After firing, the chamber end of the barrel drops to its most downward position, which brings it in line with the ejector.
In a training barrel it is necessary to omit this barrel-locking mechanism and, by so doing, the recoil action becomes pure blow-back with no up-and-down motion of the barrel. This must be done because there is not enough energy in low-energy training cartridges to precipitate sufficient recoil to unlock the barrel and the slide in their standard configurations. A training barrel of the type addressed by this invention is similar in most aspects to the standard barrel for a particular pistol with a barrel locking mechanism, but is modified, in part, by removing this locking mechanism, which holds the barrel and the slide together for the first portion of the recoil cycle.
In some 9 mm pistols, after the locking mechanism has been removed and the barrel pivoting/cam system deactivated so that the weapon can fire low-energy ammunition as represented by U.S. Pat. No. 5,359,937, the training barrel is out of line with respect to the ejector during the recoil cycle. Since barrel pivoting is no longer present, the barrel chamber must be positioned in such a way that the cartridge can be fed easily into the chamber and also be in line with the firing pin for firing. Therefore, due to this feature (of being in line with the firing pin) the chamber is out of line with the ejector in the modified weapon. This misalignment means that the spent cartridge case may not come into proper contact with the ejector, thereby causing jamming due to failure to eject.
It is, therefore, an objective of this invention to provide a training barrel system for this class of firearms that will ensure reliable ejection of the spent case upon firing.
The invention in its general form will first be described, and then its implementation in terms of specific embodiments will be detailed with reference to the drawings following hereafter. These embodiments are intended to demonstrate the principal of the invention and the manner of its implementation. The invention in its broadest and more specific forms will be further described, and defined, in each of the individual claims which conclude this specification.